A comparative study of the efficacy of fractional neodymium-doped yttrium aluminum garnet (Nd:YAG) laser therapy alone and in combination with erbium:YAG laser therapy: tracing and objective measurement of melanin index in macular amyloidosis

Macular amyloidosis (MA) is a common form of primary localized cutaneous amyloidosis, characterized by the eruption of brown pigments of the skin with a rippled pattern. MA can be of cosmetic concern for patients, and its treatment is challenging. In this study, we aimed to find new effective approaches for MA treatment. A total of 39 patients with the clinical diagnosis of MA were treated with two types of laser therapy, and the effectiveness of each approach was examined. Fractional Q-switched 10.64 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser therapy was compared with a combination of fractional Q-switched 10.64 nm Nd:YAG laser and long-pulsed fractional erbium:YAG laser therapy. Melanin biometric measurements were performed using a Mexameter, objective image-based evaluation was carried out, and the itching score and patient satisfaction were examined. Mexameter-based analysis showed that both types of laser therapy were effective in the treatment of MA, causing a significant decrease in the amount of melanin in the treated areas (P < 0.05). Also, combination of two types of laser therapy was significantly more effective than one type alone (P < 0.05). The itching score significantly decreased in patients undergoing a combination of laser therapies. Also, a positive correlation was observed between the amount of melanin and degree of itching in the treated areas. Moreover, analysis of patient satisfaction showed that more than 90% of patients had excellent satisfaction with combination laser therapy. The results confirmed the significant positive effects of both fractional Nd:YAG laser alone and in combination with fractional erbium:YAG laser therapy considering the reduction in melanin content; however, combination of two types of laser therapy was more effective than one type alone. Trial registration: IRCT200809010011​59N23